1 /* $NetBSD: dm_dev.c,v 1.8 2010/01/04 00:19:08 haad Exp $ */ 2 3 /* 4 * Copyright (c) 2008 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Adam Hamsik. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/types.h> 33 #include <sys/param.h> 34 #include <machine/thread.h> 35 #include <sys/thread2.h> 36 37 #include <sys/disk.h> 38 #include <sys/disklabel.h> 39 #include <sys/devicestat.h> 40 #include <sys/device.h> 41 #include <sys/udev.h> 42 #include <sys/devfs.h> 43 #include <sys/ioccom.h> 44 #include <sys/malloc.h> 45 #include <dev/disk/dm/dm.h> 46 47 #include "netbsd-dm.h" 48 49 extern struct dev_ops dm_ops; 50 51 struct devfs_bitmap dm_minor_bitmap; 52 uint64_t dm_dev_counter; 53 54 static dm_dev_t *dm_dev_lookup_name(const char *); 55 static dm_dev_t *dm_dev_lookup_uuid(const char *); 56 static dm_dev_t *dm_dev_lookup_minor(int); 57 58 static struct dm_dev_head dm_dev_list = 59 TAILQ_HEAD_INITIALIZER(dm_dev_list); 60 61 struct lock dm_dev_mutex; 62 63 /* dm_dev_mutex must be held by caller before using disable_dev. */ 64 static void 65 disable_dev(dm_dev_t * dmv) 66 { 67 KKASSERT(lockstatus(&dm_dev_mutex, curthread) == LK_EXCLUSIVE); 68 69 TAILQ_REMOVE(&dm_dev_list, dmv, next_devlist); 70 71 lockmgr(&dmv->dev_mtx, LK_EXCLUSIVE); 72 while (dmv->ref_cnt != 0) 73 cv_wait(&dmv->dev_cv, &dmv->dev_mtx); 74 lockmgr(&dmv->dev_mtx, LK_RELEASE); 75 } 76 /* 77 * Generic function used to lookup dm_dev_t. Calling with dm_dev_name 78 * and dm_dev_uuid NULL is allowed. 79 */ 80 dm_dev_t * 81 dm_dev_lookup(const char *dm_dev_name, const char *dm_dev_uuid, 82 int dm_dev_minor) 83 { 84 dm_dev_t *dmv; 85 86 dmv = NULL; 87 lockmgr(&dm_dev_mutex, LK_EXCLUSIVE); 88 89 /* KKASSERT(dm_dev_name != NULL && dm_dev_uuid != NULL && dm_dev_minor 90 * > 0); */ 91 if (dm_dev_minor > 0) 92 if ((dmv = dm_dev_lookup_minor(dm_dev_minor)) != NULL) { 93 dm_dev_busy(dmv); 94 lockmgr(&dm_dev_mutex, LK_RELEASE); 95 return dmv; 96 } 97 if (dm_dev_name != NULL) 98 if ((dmv = dm_dev_lookup_name(dm_dev_name)) != NULL) { 99 dm_dev_busy(dmv); 100 lockmgr(&dm_dev_mutex, LK_RELEASE); 101 return dmv; 102 } 103 if (dm_dev_uuid != NULL) 104 if ((dmv = dm_dev_lookup_uuid(dm_dev_uuid)) != NULL) { 105 dm_dev_busy(dmv); 106 lockmgr(&dm_dev_mutex, LK_RELEASE); 107 return dmv; 108 } 109 lockmgr(&dm_dev_mutex, LK_RELEASE); 110 return NULL; 111 } 112 113 114 /* 115 * Lookup device with its minor number. 116 */ 117 static dm_dev_t * 118 dm_dev_lookup_minor(int dm_dev_minor) 119 { 120 dm_dev_t *dmv; 121 122 TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) { 123 if (dm_dev_minor == dmv->minor) 124 return dmv; 125 } 126 127 return NULL; 128 } 129 /* 130 * Lookup device with it's device name. 131 */ 132 static dm_dev_t * 133 dm_dev_lookup_name(const char *dm_dev_name) 134 { 135 dm_dev_t *dmv; 136 137 TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) { 138 if (strcmp(dm_dev_name, dmv->name) == 0) 139 return dmv; 140 } 141 142 return NULL; 143 } 144 /* 145 * Lookup device with it's device uuid. Used mostly by LVM2tools. 146 */ 147 static dm_dev_t * 148 dm_dev_lookup_uuid(const char *dm_dev_uuid) 149 { 150 dm_dev_t *dmv; 151 152 TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) { 153 if (strcmp(dm_dev_uuid, dmv->uuid) == 0) 154 return dmv; 155 } 156 157 return NULL; 158 } 159 /* 160 * Insert new device to the global list of devices. 161 */ 162 int 163 dm_dev_insert(dm_dev_t * dev) 164 { 165 dm_dev_t *dmv; 166 int r; 167 168 dmv = NULL; 169 r = 0; 170 171 KKASSERT(dev != NULL); 172 lockmgr(&dm_dev_mutex, LK_EXCLUSIVE); 173 if (((dmv = dm_dev_lookup_uuid(dev->uuid)) == NULL) && 174 ((dmv = dm_dev_lookup_name(dev->name)) == NULL) && 175 ((dmv = dm_dev_lookup_minor(dev->minor)) == NULL)) { 176 177 TAILQ_INSERT_TAIL(&dm_dev_list, dev, next_devlist); 178 179 } else 180 r = EEXIST; 181 182 lockmgr(&dm_dev_mutex, LK_RELEASE); 183 return r; 184 } 185 186 /* 187 * Remove device selected with dm_dev from global list of devices. 188 */ 189 dm_dev_t * 190 dm_dev_rem(dm_dev_t *dmv, const char *dm_dev_name, const char *dm_dev_uuid, 191 int dm_dev_minor) 192 { 193 lockmgr(&dm_dev_mutex, LK_EXCLUSIVE); 194 195 if (dmv != NULL) { 196 disable_dev(dmv); 197 } else if (dm_dev_minor > 0) { 198 if ((dmv = dm_dev_lookup_minor(dm_dev_minor)) != NULL) 199 disable_dev(dmv); 200 } else if (dm_dev_name != NULL) { 201 if ((dmv = dm_dev_lookup_name(dm_dev_name)) != NULL) 202 disable_dev(dmv); 203 } else if (dm_dev_uuid != NULL) { 204 if ((dmv = dm_dev_lookup_name(dm_dev_uuid)) != NULL) 205 disable_dev(dmv); 206 } 207 208 lockmgr(&dm_dev_mutex, LK_RELEASE); 209 210 return dmv; 211 } 212 213 int 214 dm_dev_create(dm_dev_t **dmvp, const char *name, const char *uuid, int flags) 215 { 216 dm_dev_t *dmv; 217 char name_buf[MAXPATHLEN]; 218 int r, dm_minor; 219 220 if ((dmv = dm_dev_alloc()) == NULL) 221 return ENOMEM; 222 223 if (uuid) 224 strncpy(dmv->uuid, uuid, DM_UUID_LEN); 225 else 226 dmv->uuid[0] = '\0'; 227 228 if (name) 229 strlcpy(dmv->name, name, DM_NAME_LEN); 230 231 dm_minor = devfs_clone_bitmap_get(&dm_minor_bitmap, 0); 232 233 dm_table_head_init(&dmv->table_head); 234 235 lockinit(&dmv->dev_mtx, "dmdev", 0, LK_CANRECURSE); 236 cv_init(&dmv->dev_cv, "dm_dev"); 237 238 if (flags & DM_READONLY_FLAG) 239 dmv->flags |= DM_READONLY_FLAG; 240 241 aprint_debug("Creating device dm/%s\n", name); 242 ksnprintf(name_buf, sizeof(name_buf), "mapper/%s", dmv->name); 243 244 devstat_add_entry(&dmv->stats, name, 0, DEV_BSIZE, 245 DEVSTAT_NO_ORDERED_TAGS, 246 DEVSTAT_TYPE_DIRECT | DEVSTAT_TYPE_IF_OTHER, 247 DEVSTAT_PRIORITY_DISK); 248 249 dmv->devt = disk_create_named(name_buf, dm_minor, dmv->diskp, &dm_ops); 250 reference_dev(dmv->devt); 251 252 dmv->minor = minor(dmv->devt); 253 udev_dict_set_cstr(dmv->devt, "subsystem", "disk"); 254 255 if ((r = dm_dev_insert(dmv)) != 0) 256 dm_dev_destroy(dmv); 257 258 /* Increment device counter After creating device */ 259 ++dm_dev_counter; /* XXX: was atomic 64 */ 260 *dmvp = dmv; 261 262 return r; 263 } 264 265 int 266 dm_dev_destroy(dm_dev_t *dmv) 267 { 268 int minor; 269 270 /* Destroy active table first. */ 271 dm_table_destroy(&dmv->table_head, DM_TABLE_ACTIVE); 272 273 /* Destroy inactive table if exits, too. */ 274 dm_table_destroy(&dmv->table_head, DM_TABLE_INACTIVE); 275 276 dm_table_head_destroy(&dmv->table_head); 277 278 minor = dkunit(dmv->devt); 279 disk_destroy(dmv->diskp); 280 devstat_remove_entry(&dmv->stats); 281 282 release_dev(dmv->devt); 283 devfs_clone_bitmap_put(&dm_minor_bitmap, minor); 284 285 lockuninit(&dmv->dev_mtx); 286 cv_destroy(&dmv->dev_cv); 287 288 /* Destroy device */ 289 (void)dm_dev_free(dmv); 290 291 /* Decrement device counter After removing device */ 292 --dm_dev_counter; /* XXX: was atomic 64 */ 293 294 return 0; 295 } 296 297 /* 298 * dm_detach is called to completely destroy & remove a dm disk device. 299 */ 300 int 301 dm_dev_remove(dm_dev_t *dmv) 302 { 303 /* Remove device from list and wait for refcnt to drop to zero */ 304 dm_dev_rem(dmv, NULL, NULL, -1); 305 306 /* Destroy and free the device */ 307 dm_dev_destroy(dmv); 308 309 return 0; 310 } 311 312 int 313 dm_dev_remove_all(int gentle) 314 { 315 dm_dev_t *dmv, *dmv2; 316 int r; 317 318 r = 0; 319 320 lockmgr(&dm_dev_mutex, LK_EXCLUSIVE); 321 322 TAILQ_FOREACH_MUTABLE(dmv, &dm_dev_list, next_devlist, dmv2) { 323 if (gentle && dmv->is_open) { 324 r = EBUSY; 325 continue; 326 } 327 328 disable_dev(dmv); 329 dm_dev_destroy(dmv); 330 } 331 lockmgr(&dm_dev_mutex, LK_RELEASE); 332 333 return r; 334 } 335 336 /* 337 * Allocate new device entry. 338 */ 339 dm_dev_t * 340 dm_dev_alloc(void) 341 { 342 dm_dev_t *dmv; 343 344 dmv = kmalloc(sizeof(dm_dev_t), M_DM, M_WAITOK | M_ZERO); 345 346 if (dmv != NULL) 347 dmv->diskp = kmalloc(sizeof(struct disk), M_DM, M_WAITOK | M_ZERO); 348 349 return dmv; 350 } 351 /* 352 * Freed device entry. 353 */ 354 int 355 dm_dev_free(dm_dev_t * dmv) 356 { 357 KKASSERT(dmv != NULL); 358 359 if (dmv->diskp != NULL) 360 (void) kfree(dmv->diskp, M_DM); 361 362 (void) kfree(dmv, M_DM); 363 364 return 0; 365 } 366 367 void 368 dm_dev_busy(dm_dev_t * dmv) 369 { 370 lockmgr(&dmv->dev_mtx, LK_EXCLUSIVE); 371 dmv->ref_cnt++; 372 lockmgr(&dmv->dev_mtx, LK_RELEASE); 373 } 374 375 void 376 dm_dev_unbusy(dm_dev_t * dmv) 377 { 378 KKASSERT(dmv->ref_cnt != 0); 379 380 lockmgr(&dmv->dev_mtx, LK_EXCLUSIVE); 381 if (--dmv->ref_cnt == 0) 382 cv_broadcast(&dmv->dev_cv); 383 lockmgr(&dmv->dev_mtx, LK_RELEASE); 384 } 385 /* 386 * Return prop_array of dm_targer_list dictionaries. 387 */ 388 prop_array_t 389 dm_dev_prop_list(void) 390 { 391 dm_dev_t *dmv; 392 prop_array_t dev_array; 393 prop_dictionary_t dev_dict; 394 395 dev_array = prop_array_create(); 396 397 lockmgr(&dm_dev_mutex, LK_EXCLUSIVE); 398 399 TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) { 400 dev_dict = prop_dictionary_create(); 401 402 prop_dictionary_set_cstring(dev_dict, DM_DEV_NAME, dmv->name); 403 prop_dictionary_set_uint32(dev_dict, DM_DEV_DEV, dmv->minor); 404 405 prop_array_add(dev_array, dev_dict); 406 prop_object_release(dev_dict); 407 } 408 409 lockmgr(&dm_dev_mutex, LK_RELEASE); 410 return dev_array; 411 } 412 /* 413 * Initialize global device mutex. 414 */ 415 int 416 dm_dev_init(void) 417 { 418 TAILQ_INIT(&dm_dev_list); /* initialize global dev list */ 419 lockinit(&dm_dev_mutex, "dmdevlist", 0, LK_CANRECURSE); 420 devfs_clone_bitmap_init(&dm_minor_bitmap); 421 return 0; 422 } 423 424 /* 425 * Destroy all devices created in device-mapper. Remove all tables 426 * free all allocated memmory. 427 */ 428 int 429 dm_dev_uninit(void) 430 { 431 /* Force removal of all devices */ 432 dm_dev_remove_all(0); 433 434 lockuninit(&dm_dev_mutex); 435 return 0; 436 } 437